In order to prevent slippage of automobile tires on a road, e.g., snow road, various slip-preventing devices have been provided. Typically, there has been provided a well known slip-preventing device 10 as shown in FIG. 4 which includes two long-length parallel chains 13, 14 having end hooks 11, 12, and short-length chains 16 arranged between said long-length chains 13, 14 in a ladder configuration with engagements of end hooks 15 to the long-length chains. The long-length chains 13, 14 of the conventional slip-preventing device 10 are expanded on both sides of an automobile wheel or tire 17 along the circumference of the tire as shown in FIG. 5 so that the short-length chains 16 abut on a road-contacting surface of the wheel or tire 17; thereafter by a fastening of the hooks 11, 12 and an installation of a certain biasing means (not shown), an attaching operation of the slip-preventing device 10 to the tire is completed. Then, it can be used in driving on a snow road, etc., for preventing slippage of tires over snow, a frozen road, etc.
However, in the aforementioned conventional slip-preventing device, tires and road surfaces are frequently injured by high speed rotations of tires in automobile driving because the slip-preventing device is made of a metallic material. In turn, the slip-preventing device is worn away by frictions to the road surface. Therefore comfortable automobile driving is harmed and noises are occured from the slip-preventing device. Further, chains of the conventional slip-preventing device are apt to tangle each other, so that installation of the slip-preventing device would be difficult.
Therefore, it is an object of the present invention to provide a slip-preventing device which has no defect as afore-mentioned of the conventional type, effecting less injuries of tires and road surface, and comfortable drivings.